Origin of regional pressure gradients in the left ventricle during early diastole

1995 ◽  
Vol 268 (2) ◽  
pp. H550-H557 ◽  
Author(s):  
S. D. Nikolic ◽  
M. P. Feneley ◽  
O. E. Pajaro ◽  
J. S. Rankin ◽  
E. L. Yellin
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Dynamic Geometry ◽  
Major Axis ◽  
Left Ventricular ◽  
Elastic Recoil ◽  
Systolic Volume ◽  
Early Diastole ◽  
Shape Changes ◽  
Isovolumic Relaxation

Left ventricular (LV) pressure (P)-diameter, LVP-area, or LVP-volume relationships used to evaluate LV diastolic function assume uniform LV wall motion and constant LVP. Contrary to these assumptions, there are significant differences in ventricular dynamic geometry and in LV pressures measured simultaneously in different parts of the LV, particularly during early diastole. We instrumented six anesthetized open-chest dogs with three pairs of orthogonal ultrasonic crystals (anterior-posterior and septal-free wall minor axes, and base-apex major axis) and two micromanometers (in the apex and in the LV base). The mitral valve occluder was implanted during standard cardiopulmonary bypass in the mitral annulus. Data were recorded during 11 transient vena caval occlusions. The mitral valve was occluded for 1 beat every 6–8 beats during each vena caval occlusion to produce nonfilling diastole. With the decrease of the LV end-systolic volume (Ves) below the equilibrium volume Veq (volume of the completely relaxed LV at LVP = 0); the minimum negative LVP in nonfilling beats increases, the shape of the ventricle is more ellipsoidal in both filling and nonfilling beats, and the base-to-apex pressure gradient at the time of LVP minimum increases regardless of the presence or absence of filling. Thus heterogeneous myocardial stresses during isovolumic relaxation and early diastole result in ventricular shape changes, intraventricular redistribution of chamber volume, local accelerations of blood, and associated intraventricular LVP gradients. The role of elastic recoil assumes greater importance at Ves smaller than Veq, when the left ventricle becomes more ellipsoidal in shape during isovolumic relaxation, leading, in turn, to greater shape changes and greater LVP gradient.

Ventricular systolic interdependence: volume elastance model in isolated canine hearts

1987 ◽  
Vol 253 (6) ◽  
pp. H1381-H1390 ◽  
Author(s):  
W. L. Maughan ◽  
K. Sunagawa ◽  
K. Sagawa
Keyword(s):  
Left Ventricle ◽  
Right Ventricle ◽  
Cross Talk ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Ventricular Free Wall ◽  
Free Wall ◽  
Right Ventricular Free Wall ◽  
Systolic Volume ◽  
The Right

To analyze the interaction between the right and left ventricle, we developed a model that consists of three functional elastic compartments (left ventricular free wall, septal, and right ventricular free wall compartments). Using 10 isolated blood-perfused canine hearts, we determined the end-systolic volume elastance of each of these three compartments. The functional septum was by far stiffer for either direction [47.2 +/- 7.2 (SE) mmHg/ml when pushed from left ventricle and 44.6 +/- 6.8 when pushed from right ventricle] than ventricular free walls [6.8 +/- 0.9 mmHg/ml for left ventricle and 2.9 +/- 0.2 for right ventricle]. The model prediction that right-to-left ventricular interaction (GRL) would be about twice as large as left-to-right interaction (GLR) was tested by direct measurement of changes in isovolumic peak pressure in one ventricle while the systolic pressure of the contralateral ventricle was varied. GRL thus measured was about twice GLR (0.146 +/- 0.003 vs. 0.08 +/- 0.001). In a separate protocol the end-systolic pressure-volume relationship (ESPVR) of each ventricle was measured while the contralateral ventricle was alternatively empty and while systolic pressure was maintained at a fixed value. The cross-talk gain was derived by dividing the amount of upward shift of the ESPVR by the systolic pressure difference in the other ventricle. Again GRL measured about twice GLR (0.126 +/- 0.002 vs. 0.065 +/- 0.008). There was no statistical difference between the gains determined by each of the three methods (predicted from the compartment elastances, measured directly, or calculated from shifts in the ESPVR). We conclude that systolic cross-talk gain was twice as large from right to left as from left to right and that the three-compartment volume elastance model is a powerful concept in interpreting ventricular cross talk.

Left ventricular diastolic function of remodeled myocardium in dogs with pacing-induced heart failure

1998 ◽  
Vol 274 (3) ◽  
pp. H945-H954 ◽  
Author(s):  
Steven B. Solomon ◽  
Srdjan D. Nikolic ◽  
Stanton A. Glantz ◽  
Edward L. Yellin
Keyword(s):  
Heart Failure ◽  
Elastic Properties ◽  
Diastolic Pressure ◽  
Left Ventricular Diastolic Function ◽  
Left Ventricular ◽  
Diastolic Filling ◽  
Elastic Recoil ◽  
Systolic Volume ◽  
Left Ventricular Chamber ◽  
Volume Relation

In patients with heart failure, decreased contractility resulting in high end-diastolic pressures and a restrictive pattern of left ventricular filling produces a decrease in early diastolic filling, suggesting a stiff ventricle. This study investigated the elastic properties of the myocardium and left ventricular chamber and the ability of the heart to utilize elastic recoil to facilitate filling during pacing-induced heart failure in the anesthetized dog. Elastic properties of the myocardium were determined by analyzing the myocardial stress-strain relation. Left ventricular chamber properties were determined by analyzing the pressure-volume relation using a logarithmic approach. Elastic recoil was characterized using a computer-controlled mitral valve occluder to prevent transmitral flow during diastole. We conclude that, during heart failure, the high end-diastolic pressures suggestive of a stiff ventricle are due not to stiffer myocardium but to a ventricle whose chamber compliance characteristics are changed due to geometric remodeling of the myocardium. The restrictive filling pattern is a result of the ventricle being forced to operate on the stiff portion of the diastolic pressure-volume relation to maintain cardiac output. Slowed relaxation and decreased contractility result in an inability of the heart to contract to an end-systolic volume below its diastolic equilibrium volume. Thus the left ventricle cannot utilize elastic recoil to facilitate filling during heart failure.

Numerical Study on Diastolic Left Ventricular Hemodynamics Using Motion Models of Mitral Valve With/Without Edge-to-Edge Repair

2010 ◽  
Author(s):  
Yingying Hu ◽  
Liang Shi ◽  
Siva Parameswaran ◽  
Sergey A. Smirnov ◽  
Zhaoming He
Keyword(s):  
Shear Stress ◽  
Mitral Valve ◽  
Left Ventricle ◽  
Platelet Activation ◽  
Numerical Study ◽  
Left Ventricular ◽  
High Shear ◽  
High Shear Stress ◽  
Orifice Area ◽  
Motion Models

Edge-to-edge repair (ETER) is a newly developed technique to correct such mitral valve (MV) malfunctions as regurgitation [1,2]. This technique changes MV geometric configuration by suturing the anterior and posterior leaflets at central or commissural edges, and consequently alters MV and left ventricle (LV) dynamics. For instance, stress in the MV elevated due to ETER may cause leaflets tearing near suture. Little has been known about shear stress on the MV and LV walls under MV ETER conditions, where high shear stress might cause platelet activation or hemolysis [3]. When ETER is done at the central leaflet edges, it generates two MV orifices, leads to two deflected jets, and completely changes vortices in the LV. ETER also reduces the orifice area, and increases jet velocity and transmitral pressure [1,2,4]. Flow patterns in the LV and ETER effects on the LV and MV functions have not been understood well.

Relationship between diastolic shape (eccentricity) and passive elastic properties in canine left ventricle

1990 ◽  
Vol 259 (2) ◽  
pp. H457-H463 ◽  
Author(s):  
S. D. Nikolic ◽  
E. L. Yellin ◽  
M. Dahm ◽  
O. Pajaro ◽  
R. W. Frater
Keyword(s):  
Regression Analysis ◽  
Linear Regression ◽  
Elastic Properties ◽  
Diastolic Pressure ◽  
Linear Regression Analysis ◽  
Left Ventricular ◽  
Elastic Recoil ◽  
Systolic Volume ◽  
End Systolic Volume ◽  
Lv Volume

This study was designed to investigate the relationship between left ventricular (LV) eccentricity, volume, and passive elastic properties. Eight open-chest fentanyl-anesthetized dogs were instrumented with an LV micromanometer, a remote-controlled mitral valve occluder, and two pairs of ultrasonic crystals to measure anterior-posterior and base-apex dimensions. We identified the presence of elastic recoil forces with negative LV diastolic pressure in nonfilling diastoles (end-systolic volume clamp). Using linear regression analysis we related midwall eccentricity to volume in nonfilling diastoles at the time of LVPmin and at end diastole, and in normal beats at end systole at LVPmin and at end-diastole. Intersection of the end-systolic and end-diastolic lines (transitional volume, Vt = 38.0 + 6.4 ml) divides cycles with and without the presence of elastic recoil forces. Vt is analogous to the equilibrium volume (V0), determined as the volume intercept of the logarithmic passive pressure-volume (P-V) relationship using LV volume estimated from LV weights (V0 nl = 37.6 + 4.4 ml), or the volume intercept of the linearized P-V relationship calculated from a prolate spheroidal model using measured minor and major diameters (V0 l = 44.5 + 3.5 ml). Linear regression analysis was also used to relate the square of peak mitral flow (MF2) with the corresponding atrioventricular pressure gradient (delta P); the slope represents a dissipative constant for the cycles without, P = 0.00058(MF)2 + 0.35 (n = 48, r = 0.73), and with elastic recoil P = 0.00035(MF)2 + 0.21 (n = 24, r = 0.81).(ABSTRACT TRUNCATED AT 250 WORDS)

Dimensional analysis of the left ventricle: effects of acute aortic regurgitation

1975 ◽  
Vol 228 (2) ◽  
pp. 536-542 ◽  
Author(s):  
SJ Leshin ◽  
LD Horwitz ◽  
JH Mitchell
Keyword(s):  
Left Ventricle ◽  
Aortic Regurgitation ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Systolic Volume ◽  
Severe Aortic Regurgitation ◽  
End Diastolic Volume ◽  
Catheter Technique ◽  
End Systolic Volume

The effects of acute severe aortic regurgitation on the left ventricle were investigated in conscious, chronically instrumented dogs. Left ventricular dimensions and volumes were measured from biplane cineradiographs of beads positioned near the endocardium. Data were collected before and after the production of aortic regurgitation by a catheter technique. The aortic regurgitation resulted in increases in mean aortic pulse pressure from 44 to 73 mmHg (P smaller than 0.001), heart rate from 87 to 122 beats/min (P smaller than 0.02), and left ventricular end-diastolic pressure from 11 to 25 mmHg (P smaller than 0.05). Mean end-diastolic volume rose from 61 to 69 cc (P smaller than 0.001), while end-systolic volume remained unchanged at 37 cc. The end-diastolic dilatation following regurgitation was asymmetrical in that the increase in size was due principally to an increase in the septal-lateral axis. The acute volume load of aortic regurgitation was accomplished by an increase in end-diastolic volume, i.e., the Frank-Starling mechanism. The tachycardia probably reflects augmented cardiac sympathetic activity, but the constant end-systolic volume at a similar mean systolic pressure suggests that the net contractile state was unchanged.

Measurements of changes in left ventricular volume, strain, and twist during isovolumic relaxation using MRI

2010 ◽  
Vol 298 (6) ◽  
pp. H1908-H1918 ◽  
Author(s):  
June Cheng-Baron ◽  
Kelvin Chow ◽  
Nee Scze Khoo ◽  
Ben T. Esch ◽  
Jessica M. Scott ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Volume Change ◽  
Ventricular Volume ◽  
Apparent Volume ◽  
Left Ventricular ◽  
Aortic Valves ◽  
Apparent Increase ◽  
Volume Measurements ◽  
Lv Volume ◽  
Isovolumic Relaxation

Left ventricular (LV) active relaxation begins before aortic valve closure and is largely completed during isovolumic relaxation (IVR), before mitral valve opening. During IVR, despite closed mitral and aortic valves, indirect assessments of LV volume have suggested volume increases during this period. The aim of this study is to measure LV volume throughout IVR and to determine the sources of any volume changes. For 10 healthy individuals (26.0 ± 3.8 yr), magnetic resonance imaging was used to measure time courses of LV volume, principal myocardial strains (circumferential, longitudinal, radial), and LV twist. Mitral leaflet motion was observed using echocardiography. During IVR, LV volume measurements showed an apparent increase of 4.6 ± 1.5 ml (5.0 ± 2.0% of the early filling volume change), the LV untwisted by 4.5 ± 1.9° (36.6 ± 18.0% of peak systolic twist), and changes in circumferential, longitudinal, and radial strains were +0.87 ± 0.64%, +0.93 ± 0.57%, and −1.46 ± 1.66% (4.2 ± 3.3%, 5.9 ± 3.3%, and 5.3 ± 7.5% of peak systolic strains), respectively. The apparent changes in volume correlated ( P < 0.01) with changes in circumferential, longitudinal, and radial strains ( r = 0.86, 0.69, and −0.37, respectively) and untwisting ( r = 0.83). The closed mitral valve leaflets were observed to descend into the LV throughout IVR in all subjects in apical four- and three-chamber and parasternal long-axis views by 6.0 ± 3.3, 5.1 ± 2.4, and 2.1 ± 5.0 mm, respectively. In conclusion, LV relaxation during IVR is associated with changes in principal strains and untwisting, which are all correlated with an apparent increase in LV volume. Since closed mitral and aortic valves ensure true isovolumic conditions, the apparent volume change likely reflects expansion of the LV myocardium and the inward bowing of the closed mitral leaflets toward the LV interior.

Echocardiographic factors discriminating biventricular versus univentricular approach in the foetus with borderline left ventricle

2014 ◽  
Vol 25 (5) ◽  
pp. 941-950 ◽  
Author(s):  
David W. Jantzen ◽  
Sarah K. Gelehrter ◽  
Sunkyung Yu ◽  
Janet E. Donohue ◽  
Carlen G. Fifer
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Single Ventricle ◽  
Left Ventricular ◽  
Z Score ◽  
Biventricular Repair ◽  
Z Scores ◽  
Valve Annulus ◽  
Single Ventricle Palliation ◽  
Dimension Ratio

AbstractBackground: The term “borderline left ventricle” describes a small left heart that may be inadequate to provide systemic cardiac output and implies the potential need for a single-ventricle palliation. The aim of this study was to identify foetal echocardiographic features that help discriminate which infants will undergo single-ventricle palliation versus biventricular repair to aid in prenatal counselling. Methods: The foetal database at our institution was searched to identify all foetuses with borderline left ventricle, as determined subjectively by a foetal cardiologist, from 2000 to 2011. The foetal images were retrospectively analysed for morphologic and physiologic features to determine which best predicted the postnatal surgical choice. Results: Of 39 foetuses identified with borderline left ventricle, 15 were planned for a univentricular approach, and 24 were planned for a biventricular approach. There were significant differences between the two outcome groups in the Z-scores of the mitral valve annulus, left ventricular end-diastolic dimension, aortic valve annulus, and ascending aorta diameter (p<0.05). With respect to discriminating univentricular outcomes, cut-offs of mitral valve Z-score ⩽−1.9 and tricuspid:mitral valve ratio ⩾1.5 were extremely sensitive (100%), whereas a right:left ventricular end-diastolic dimension ratio ⩾2.1 provided the highest specificity (95.8%). Conclusion: In foetuses with borderline left ventricle, a mitral valve Z-score ⩾−1.9 or a tricuspid:mitral valve ratio ⩽1.5 suggests a high probability of biventricular repair, whereas a right:left ventricular end-diastolic dimension ratio ⩾2.1 confers a likelihood of single-ventricle palliation.

scholarly journals Early Left Ventricular Systolic and Diastolic Dysfunction in Patients with Newly Diagnosed Obstructive Sleep Apnoea and Normal Left Ventricular Ejection Fraction

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Lisulov Popovic Danica ◽  
Mirjana Krotin ◽  
Marija Zdravkovic ◽  
Ivan Soldatovic ◽  
Darko Zdravkovic ◽  
...  
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Ejection Fraction ◽  
Tissue Doppler ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Lv Function ◽  
Newly Diagnosed ◽  
Mitral Flow ◽  
Obstructive Sleep

The aim of the study was to evaluate whether obstructive sleep apnea (OSA) contributes directly to left ventricular (LV) diastolic and regional systolic dysfunction in newly diagnosed OSA with normal left ventricle ejection fraction.Methods. 125 consecutive patients were prospectively enrolled in the study. Control group consisted of 78 asymptomatic age-matched healthy subjects who did not have any cardiovascular and respiratory diseases. All patients had undergone overnight polysomnography and standard transthoracic and tissue Doppler imaging echocardiogram.Results. TheE/Aratio and the peakEwave at mitral flow were significantly lower and the peakAwave at mitral flow was significantly higher in OSA patients compared with control subjects. Left ventricle isovolumetric relaxation time (IVRT) and mitral valve flow propagation (MVFP) were significantly longer in OSA patients than in controls. Tissue Doppler derivedS′amplitude of lateral part at mitral valve (S′Lm) andE′wave amplitudes both at the lateral (E′Lm) and septal parts of the mitral valve (E′Sm) were significantly lower in OSA patients compared to controls.Conclusion. Newly diagnosed OSA patients with normal global LV function have significantly impaired diastolic function and regional longitudinal systolic function. OSA is independently associated with these changes in LV function.

scholarly journals Surgical treatment of secondary mitral regurgitation in heart failure: a present-day view

2021 ◽  
Vol 13 (1) ◽  
pp. 40-48
Author(s):  
E. G. Agafonov ◽  
M. A. Popov ◽  
D. I. Zybin ◽  
D. V. Shumakov
Keyword(s):  
Heart Failure ◽  
Mitral Valve ◽  
Left Ventricle ◽  
Mitral Regurgitation ◽  
Volume Overload ◽  
Left Ventricular ◽  
Functional Class ◽  
Functional Mitral Regurgitation ◽  
Admission Rates ◽  
Replacement Surgery

Rationale. Secondary, or functional, mitral regurgitation is the most common complication of heart failure. Dysfunction of one or more mitral valve structures occurs in 39–74% of patients thus complicating the course of the disease and significantly worsening the prognosis in patients with left ventricle dilatation. An unfavorable prognosis in patients with the development of mitral regurgitation is conditioned by the progressive changes that form a vicious circle: the continuing volume overload and dilatation of the left ventricle cause its remodeling, leading to further dilatation of the mitral valve annulus. Dysfunctions of the papillary muscles lead to the increased tension of the left ventricle wall and increased mitral regurgitation. Clinically, this process is manifested by the congestive heart failure progression and worsened prognosis of the further course, which in the future may lead to considering the inclusion of this patient group on the waiting list for heart transplantation.Purpose. The purpose of this article is to review the role of surgical management in patients with heart failure complicated by mitral regurgitation.Conclusions. The main principles of the treatment for functional mitral regurgitation include the reverse left ventricular remodeling and mitral valve repair or replacement surgery which lead to an improved quality of life, the transition of patients to a lower functional class, reduced hospital admission rates, and also to a regression or slower progression of the heart failure and to an improved survival.

scholarly journals Correlation between echocardiographic parameters of left ventricle and glycosylated hemoglobin in children with type 1 Diabetes Mellitus

2022 ◽  
Vol 3 (1) ◽  
pp. 44-52
Author(s):  
Valeriu ESANU ◽  
Ina PALII
Keyword(s):  
Diabetes Mellitus ◽  
Type 1 Diabetes ◽  
Left Ventricle ◽  
Type 1 Diabetes Mellitus ◽  
Wall Thickness ◽  
Structural Parameters ◽  
Glycosylated Hemoglobin ◽  
Left Ventricular ◽  
Systolic Volume

Introduction. Deterioration of left ventricular (LV) parameters in Diabetes Mellitus (DM) can occur in the absence of other heart problems. An association between glycosylated hemoglobin (HbA1c) and changes of the LV parameters in DM has been reported. However, data regarding this association model in children with Type 1 Diabetes Mellitus (T1DM) are limited. The purpose of the work was to investigate the association between HbA1c and the LV parameters in pediatric patients. Material and methods. The study was conducted on 28 children with T1DM ((aged 10 - 18 years, gender M (15)/F (13), duration ≥5 years). The clinical (standard medical examination) and paraclinical (biochemical dosage – HbA1c, echocardiography – LV functional and structural parameters) data was carried out. Statistical analysis  used the SPSS version 20. Results. The correlational study between the HbA1c and the LV parameters revealed a statistically significant positive correlation coefficient with aortic root diameter (mm) (r=0.7**, p<0.001), left atrium (mm) (r=0.8**, p<0.001 LV diastolic diameter (mm) (r=0.7**, p<0.001), LV systolic diameter (mm) (r=0.7**, p<0.001), septal wall thickness (mm) (r=0.5*, p=0.036), posterior wall thickness (mm) (r=0.5*, p=0.032), LV diastolic volume (ml) (r=0.5*, p=0.025), LV systolic volume (ml) (r=0.6**, p=0.01), ejection fraction (%) (r=0.7**, p=0.001), fractional shortening (%) (r=0.6**, p=0.002). Conclusions. The results of the study show that in children with T1DM, the increase value of the HbA1c is associated with a consensual and proportional increase in the values of the parameters of the left ventricle.  

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